In one of her videos, she talks about a friend who says she's obsessing too much. The fangirl was upset with this friend and was going to break off the friendship. All of the commenters thought it was because she couldn't tolerate a friend who didn't like what she liked, but I think it was because the fangirl felt like she was being judged.

As you've said, once you discover you're successful at something, you can't stop.